Congrats on wanting to know more - you remind me of me when I was around 25 and realized I didn't know much about the church I had been raised in.
The Gospel Principles class was especially designed for new members, investigators, and people who need or want a brush up in the basics. I'd suggest going to that, instead of taking the discussions.
Other ways to do what you want:
* Go on splits with missionaries
* Teach the Gospel Principles class
*
Read the book without going to class at all.